1. Field of the Invention
The present invention relates to a puncture preventive sealant filled in a sealant chamber defined in a tube adjacently to an air chamber.
2. Description of Related Art
Japanese Patent Laid-open No. Sho 50-72303 discloses a technique in which a sealant containing a fiber component is enclosed in a tire tube of an automobile for repairing damage to the tube. For example, if the tube is pierced by a nail or the like, the sealant prevents leakage of air from the tube. This sealant contains short-fibers and a fine crystal powder of cellulose in a liquid polymer or an aqueous solution, wherein the ratio of the fine crystal powder of cellulose is set to be larger than that of the short-fibers for suppressing the flow of the short-fibers in the tube.
The above-described sealant has been developed from the viewpoint of an extensive flow of a sealant in a tube, and has been configured wherein the content of the fine crystal powder of cellulose is set to be larger than that of the short-fibers for suppressing the flow of the short-fibers in the tube. Such a sealant, however, has a problem since the fine crystal powder of cellulose is produced by processing cellulose fibers and thereby it is higher in cost than the cellulose fibers, with a result that the increased content of the fine crystal powder of cellulose leads to a significantly increased cost.